OfflineAudioContext.startRendering() should return a Promise: - https://www.w3.org/TR/webaudio/#dom-offlineaudiocontext-startrendering
Created attachment 405509 [details] Patch
Created attachment 405524 [details] Patch
Created attachment 405530 [details] Patch
Created attachment 405532 [details] Patch
Committed r265086: <https://trac.webkit.org/changeset/265086> All reviewed patches have been landed. Closing bug and clearing flags on attachment 405532 [details].
<rdar://problem/66331479>